1. Field of the Invention
The present invention relates to ultrasound and more particularly to ultrasound devices used for imaging, cutting or removal of tissue and/or matter from a living body.
2. Description of Related Art
Probes or scalpels for the fragmentation and removal of materials, tissue and fluids from living beings are known to the art. For example, U.S. Pat. No. 2,227,727, issued Jan. 7, 1941 to Vincent Leggiardro, discloses an apparatus for fragmenting naturally formed stones, such as kidney stones, and the like, utilizing a high speed reciprocating rod which may have a blunt end, a sharp or chisel point, a cutting blade, or combination thereof, such as a cutting blade having a blunt end.
A particular arrangement in an ultrasonically vibrated surgical tool using an irrigation fluid and an anti-coagulant is disclosed in U.S. Pat. No. 4,493,694, issued Jan. 15, 1985, to David G. Wuchinich, utilizes a hollow tool having a suction passage and at least one preaspirating orifice in the wall of the tool, and a plastic sleeve concentrically spaced about the tool for admitting fluid from a supply into the space between the tool and passing substantially all of the fluid through the preaspirating orifice.
In the application of ultrasonics to liposuction, instruments of varying configurations recently have been proposed. In U.S. Pat. No. 5,236,414, issued Aug. 17, 1993 to Katsuya-Takasu, a tubular body defining a suction passage has an opening in its front lower end, and an outer tube having a corresponding opening, by means of which fat tissue is crushed and/or emulsified due to the vibration of the front end of the tubular body and is then aspirated. In U.S. Pat. No. 5,514,086, issued May 7, 1996, to Parisi et al., an ultrasonically vibrated hollow probe has a port in its surface for aspiration and a tip substantially formed of plastic.
While the use of ultrasound has proven effective, its use must be carefully controlled. For example, external ultrasonic power is often used in order to ease the internal lipoplasty operation by breaking down the membranes of fat cells. A surgeon performing such a procedure has no feedback on how much energy is delivered over any given time span within a given area of treatment. Ultrasonic cutting and fragmentation tools suffer from the same limitation. Because of the importance of ultrasound treatments, a need exists for a method of measuring and controlling the energy delivered during the ultrasound treatment.
A method and apparatus are provided for applying an ultrasound treatment to a portion of a human body. The method includes the steps of determining a temperature rise which the body portion will experience when a dosage limit of the ultrasound treatment has been reached. The method further includes the steps of disposing on the body portion an indicator adapted to provide a visual change at the determined temperature and applying ultrasound to the body portion until the indicator provides the visual change at the determined temperature.